Color

#1d379f

#1d379f
hex#1d379f
rgbrgb(29, 55, 159)
hslhsl(228, 69%, 37%)
oklchoklch(0.392 0.171 266.8)
Closest name: Depths of Night (#2c319b)Relative luminance 0.055

Colors that go with #1d379f

Charcoal, Steel Blue and Blue lead the list. Each partner is a real named colour with the reason it works — a wheel relationship, a neutral that carries it, or a pairing lifted from a palette or brand system that actually shipped — and every pair opens in the palette tool.

Tints & shades

Every swatch is its own page — click any to analyze it.

Harmonies

Complementary

Open in tool →

#9f851d

#1d789f · #441d9f

#9f1d37 · #379f1d

Split-complementary

Open in tool →

#9f441d · #789f1d

#9f1d78 · #9f851d · #1d9f44

Contrast

#1d379f as textRatioAAAA largeAAAFix
Aaon white
10:1passpasspassPasses AAA — no fix needed.
Aaon black
2.1:1failfailfail
  • AA: use #536fdf as the text (4.71:1)
  • AAA: use #7e93e7 as the text (7.21:1)
  • AA: or shift the background to #b0b0b0 (4.61:1)
  • AAA: or shift the background to #d9d9d9 (7.09:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #1d379f as the background.

Brands using this color

No public brand in the corpus uses this exact color yet. Extract a brand to add one.

Fonts for this mood

#1d379f reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #1d379f
live endpoint

Point any MCP client at the shared colors endpoint and your agent gets the same engine as this page — direct_palette, edit_direction, check_palette, check_contrast — read-only, no key. Every direction it proposes comes with a /colors/d/… link: open it, lock what you like, paste the link back, and the agent edits rather than re-rolls.

endpointhttps://mcp.brandsweets.com/colors/mcp
claude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
try this prompt

analyze #1d379f and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/1d379f-9c9fc4-df7c4e-231f2d-e9eff1?lock=0&style=vibrant

Want the agent to remember your picks and write them into a living brand? Create a free BrandSweets workspace.

Machine-readable: color.md